+
+
+## ------------------------------------------------------------------------- ##
+## Leaked semantic values when reporting ambiguity. ##
+## ------------------------------------------------------------------------- ##
+
+AT_SETUP([Leaked semantic values when reporting ambiguity])
+
+AT_DATA_GRAMMAR([glr-regr15.y],
+[[
+%glr-parser
+%destructor { parent_rhs_before_value = 0; } parent_rhs_before
+
+%{
+# include <stdlib.h>
+ static void yyerror (char const *);
+ static int yylex (void);
+ static int parent_rhs_before_value = 0;
+# define USE(val)
+%}
+
+%%
+
+start:
+ alt1 %dprec 1
+ | alt2 %dprec 2
+ ;
+
+/* This stack must be merged into the other stacks *last* (added at the
+ beginning of the semantic options list) so that yyparse will choose to clean
+ it up rather than the tree for which some semantic actions have been
+ performed. Thus, if yyreportAmbiguity longjmp's to yyparse, the values from
+ those other trees are not cleaned up. */
+alt1: ;
+
+alt2:
+ parent_rhs_before ambiguity {
+ USE ($1);
+ parent_rhs_before_value = 0;
+ }
+ ;
+
+parent_rhs_before:
+ {
+ USE ($$);
+ parent_rhs_before_value = 1;
+ }
+ ;
+
+ambiguity: ambiguity1 | ambiguity2 ;
+ambiguity1: ;
+ambiguity2: ;
+
+%%
+
+static void
+yyerror (char const *msg)
+{
+ fprintf (stderr, "%s\n", msg);
+}
+
+static int
+yylex (void)
+{
+ static int called;
+ if (called++)
+ abort ();
+ return 0;
+}
+
+int
+main (void)
+{
+ int exit_status = yyparse () != 1;
+ if (parent_rhs_before_value)
+ {
+ fprintf (stderr, "`parent_rhs_before' destructor not called.\n");
+ exit_status = 1;
+ }
+ return exit_status;
+}
+]])
+
+AT_BISON_CHECK([[-o glr-regr15.c glr-regr15.y]], 0, [],
+[glr-regr15.y: conflicts: 2 reduce/reduce
+])
+AT_COMPILE([glr-regr15])
+
+AT_PARSER_CHECK([[./glr-regr15]], 0, [],
+[syntax is ambiguous
+])
+
+AT_CLEANUP
+
+
+## ------------------------------------------------------------------------- ##
+## Leaked lookahead after nondeterministic parse syntax error. ##
+## ------------------------------------------------------------------------- ##
+
+AT_SETUP([Leaked lookahead after nondeterministic parse syntax error])
+AT_DATA_GRAMMAR([glr-regr16.y],
+[[
+%glr-parser
+%destructor { lookahead_value = 0; } 'b'
+
+%{
+# include <stdlib.h>
+ static void yyerror (char const *);
+ static int yylex (void);
+ static int lookahead_value = 0;
+# define USE(val)
+%}
+
+%%
+
+start: alt1 'a' | alt2 'a' ;
+alt1: ;
+alt2: ;
+
+%%
+
+static void
+yyerror (char const *msg)
+{
+ fprintf (stderr, "%s\n", msg);
+}
+
+static int
+yylex (void)
+{
+ static char const input[] = "ab";
+ static size_t toknum;
+ if (! (toknum < sizeof input))
+ abort ();
+ if (input[toknum] == 'b')
+ lookahead_value = 1;
+ return input[toknum++];
+}
+
+int
+main (void)
+{
+ int exit_status = yyparse () != 1;
+ if (lookahead_value)
+ {
+ fprintf (stderr, "Lookahead destructor not called.\n");
+ exit_status = 1;
+ }
+ return exit_status;
+}
+]])
+
+AT_BISON_CHECK([[-o glr-regr16.c glr-regr16.y]], 0, [],
+[glr-regr16.y: conflicts: 1 reduce/reduce
+])
+AT_COMPILE([glr-regr16])
+
+AT_PARSER_CHECK([[./glr-regr16]], 0, [],
+[syntax error
+])
+
+AT_CLEANUP
+
+
+## ------------------------------------------------------------------------- ##
+## Uninitialized location when reporting ambiguity. ##
+## ------------------------------------------------------------------------- ##
+
+AT_SETUP([Uninitialized location when reporting ambiguity])
+AT_DATA_GRAMMAR([glr-regr17.y],
+[[
+%glr-parser
+%locations
+%define api.pure
+%error-verbose
+
+%union { int dummy; }
+
+%{
+ static void yyerror (YYLTYPE *, char const *);
+ static int yylex (YYSTYPE *, YYLTYPE *);
+%}
+
+%initial-action {
+ @$.first_line = 1;
+ @$.first_column = 1;
+ @$.last_line = 1;
+ @$.last_column = 1;
+}
+
+%%
+
+/* Tests the case of an empty RHS that has inherited the location of the
+ previous nonterminal, which is unresolved. That location is reported as the
+ last position of the ambiguity. */
+start: ambig1 empty1 | ambig2 empty2 ;
+
+/* Tests multiple levels of yyresolveLocations recursion. */
+ambig1: sub_ambig1 | sub_ambig2 ;
+ambig2: sub_ambig1 | sub_ambig2 ;
+
+/* Tests the case of a non-empty RHS as well as the case of an empty RHS that
+ has inherited the initial location. The empty RHS's location is reported as
+ the first position in the ambiguity. */
+sub_ambig1: empty1 'a' 'b' ;
+sub_ambig2: empty2 'a' 'b' ;
+empty1: ;
+empty2: ;
+
+%%
+
+static void
+yyerror (YYLTYPE *locp, char const *msg)
+{
+ fprintf (stderr, "Error at %d.%d-%d.%d: %s.\n", locp->first_line,
+ locp->first_column, locp->last_line, locp->last_column, msg);
+}
+
+static int
+yylex (YYSTYPE *lvalp, YYLTYPE *llocp)
+{
+ static char const input[] = "ab";
+ static size_t toknum;
+ if (! (toknum < sizeof input))
+ abort ();
+ lvalp->dummy = 0;
+ llocp->first_line = llocp->last_line = 2;
+ llocp->first_column = toknum + 1;
+ llocp->last_column = llocp->first_column + 1;
+ return input[toknum++];
+}
+
+int
+main (void)
+{
+ return yyparse () != 1;
+}
+]])
+
+AT_BISON_CHECK([[-o glr-regr17.c glr-regr17.y]], 0, [],
+[glr-regr17.y: conflicts: 3 reduce/reduce
+])
+AT_COMPILE([glr-regr17])
+
+AT_PARSER_CHECK([[./glr-regr17]], 0, [],
+[Error at 1.1-2.3: syntax is ambiguous.
+])
+
+AT_CLEANUP
+
+
+## -------------------------------------------------------------##
+## Missed %merge type warnings when LHS type is declared later. ##
+## -------------------------------------------------------------##
+
+AT_SETUP([Missed %merge type warnings when LHS type is declared later])
+AT_DATA_GRAMMAR([glr-regr18.y],
+[[%glr-parser
+
+%{
+ #include <stdlib.h>
+ static void yyerror (char const *);
+ static int yylex ();
+%}
+
+%union {
+ int type1;
+ int type2;
+ int type3;
+}
+
+%%
+
+sym1: sym2 %merge<merge> { $$ = $1; } ;
+sym2: sym3 %merge<merge> { $$ = $1; } ;
+sym3: %merge<merge> { $$ = 0; } ;
+
+%type <type1> sym1;
+%type <type2> sym2;
+%type <type3> sym3;
+
+%%
+
+static void
+yyerror (char const *msg)
+{
+ fprintf (stderr, "%s\n", msg);
+}
+
+static int
+yylex ()
+{
+ static int called;
+ if (called++)
+ abort ();
+ return 0;
+}
+
+int
+main (void)
+{
+ return yyparse ();
+}
+]])
+
+AT_BISON_CHECK([[-o glr-regr18.c glr-regr18.y]], 1, [],
+[glr-regr18.y:26.18-24: result type clash on merge function `merge': <type2> != <type1>
+glr-regr18.y:25.18-24: previous declaration
+glr-regr18.y:27.13-19: result type clash on merge function `merge': <type3> != <type2>
+glr-regr18.y:26.18-24: previous declaration
+])
+
+AT_CLEANUP